Interpreting the aquifer in the Limbungan Village, Rumbai Pesisir District, Pekanbaru City using the Schlumberger geoelectric method

Abstract

The availability of groundwater in Limbungan Village, Rumbai Pesisir District, Pekanbaru City is crucial for ensuring clean water for local communities. Because subsurface geological conditions vary, aquifer characteristics also differ, making it necessary to identify the aquifer’s presence and properties using an effective method. This study applies the Schlumberger configuration geoelectrical method to characterize the aquifer based on the distribution of subsurface resistivity values. Measurements were conducted along two profiles of 100 m each using a resistivity meter. The collected field data (current and potential difference) were processed with IPI2WIN software to generate a resistivity-depth model using one-dimensional (1D) inversion. The results indicate that subsurface resistivity values range from 6.94 Ωm to 259 Ωm, with a low inversion error of 3.66%, demonstrating good agreement between field measurements and the model. The subsurface materials consist of fine- to coarse-grained lithologies, including clay, silt, fine sand, coarse sand, and gravel. Aquifer zones were identified in the 5th and 6th layers, showing resistivity values of 186 Ωm and 259 Ωm, with thicknesses greater than 60 m. These resistivity characteristics suggest coarse-grained formations with high porosity and permeability, implying strong potential for groundwater storage and flow. Vertically, the aquifer occurs at depths of approximately ± 6 m to more than 70 m and is interpreted as a relatively stable confined aquifer. Overall, the Schlumberger geoelectric method proves effective for non-destructive aquifer identification and can serve as a reference for groundwater resource exploration.